Method of manufacturing spark-plugs.



J. G. ANDERSON. METHOD OF MA'NUFAUTURING SPARK PLUGS.

APPLIOATION FILED AUG. 5, 1909.

Patented Aug. 9, 1910.

W1 theme:

' UNITED STATES PATENT OFFICE.

JAMES C. ANDERSON, OF WASHINGTON,DISTRICT OF COLUMBIA.

METHOD OF MANUFACTURING SPARK-PLUGS.

Specification of Letters Patent.

Patented Aug. 9, 1910.

Application filed August 5, 1909. Serial No. 511,409.

'able others skilled in the art to which it appertains to make and use the same.

My invention relates to a new and useful method of manufacturing spark-plugs, havingv the generic features described and claimed in Letters Patent granted to me July 7, 1903, No. 732,812, and particularly of such construction as is illustrated as being produced by a novel construction of molds shown and described in another application filed by me on even date herewith, Serial No. 511,408, and in which the central electrode terminates in a chamber in the inner end of the insulating glass;

For the purpose of making clear my improved method, I shall refer to the accompanying drawing which is a reproduction of the drawing constituting a part of the application hereinbefore referred to.

Figure 1 is a top or plan view of the mold in which the spark plug is made. Fig. 2 is a central vertical section of the same. Fig. 3 is a horizontal section on the line a-b of Fig. 2; and Fig. 4 is a similar section on the line 6-0 of Fig. 2.

1 Similar reference numerals indicate like parts in the several figures of the drawing.

Before referring particularly to the mold which I employ in carrying out my improved mcthod, I deem it important to call attention to the fact that while the principal feature of my invention consistsin molding the insulating glass between the metallic parts of the s ark plug and welding it therewith, it di ers essentially from the ordinary method of molding glass in the fact that instead of compressing the glass within a non-heated mold from which it is subsequently removed,- I deposit the molten glass within the spark plug shell confined within the mold, and that such shell, as well as the electrode, are heatedlto such temperature that when the molten glass between the two is subjected to compresslon, it is welded with the shell and the electrode.

In the drawings, 1 is the base of the mold to which the members 2 and 3 are pivoted at 4, which are operated by handles 5 and 6, and which embrace the shell 7 of a spark plug, and 8, is a plunger to the lower extremity of which is secured a die 9, and within which die and plunger is a seat adapted to receive one end of an electrode 10, held by friction of a spring 11, all as fully described in the application hereinbefore referred to. v

With a mold substantially such as shown, I first locate within the base of the mold an attenuated terminal 12 for the electrode; I

then heat to a proper degree a shell 7, and locate the same upon or within a seat in the base part of the mold; an electrode 10, is then heated and seated within the end of ger 8, or a die secured thereto, contacts with and compresses the molten glass within the shell 7, and owing to the temperature of the shell, electrode, and glass, producesva perfect weld between the glass, and the metallic parts of the spark plug.

While in the drawings I have shown the electrode as seated by friction within the end of the plunger and designed to be forced within and through the body of molten glass w1th1n the shell, the electrode may be seated and supported within the base of the mold and the plunger formed with a recess or chamber adapted to receive the exposed end of the electrode, as described in the application hereinbefore referred to.

I do not wish to be confined to any-particular manner of assembling the shell and electrode with reference to the body of molten glass deposited within the shell, as the genus of my improved method resides 1n supporting the shell within the mold, locating the electrode within the shell, the shell and electrode being previously heated to a proper degree, then depositing within the shell a suitable quantity of molten glass, and finally subjecting the glass to pressure to complete the method.

Having described the method of manufacturing spark plugs of the character described, what I claim as new and desire to Secure by Letters Patent is 1. The method of manufacturing spark plugs. which consists in heating the shell and confining it within a mold, locating a heated electrode within the shell and supporting it in fixed relations therewith, flowing molten glass between the shell and the electrode, and finally subjecting the body of molten glass to pressure whereby the same is welded to the metallic members of theplug, substantially as herein before set forth.

2. The method herein described, of manufacturing spark plugs which consists in locating within the base of a mold a heated shell. and confining the same in fixed position therein by embracing it with the pivoted members of the mold; seating within the lower extremity of a compressing plunger a heated electrode; depositing a suitable quantity of molten glass within the shell; and finally causing the plunger to descend to carry the electrode through the body of molten glass and to weld the latter with the electrode and shell.

3. The method herein described of'manufacturing spark plugs which consists in supporting the attenuated and highly conductive terminal of the electrode within the base of a mold; heating a shell and'support- .mold; heating an electrode havin ing it upon the base of the mold, and confining it within pivoted members of the a bifurcated seat at its lower extremity tor the reception of the attenuated terminal; separably connecting the upper extremity of the electrode with the lower extremity of a compression plunger; depositing a body of molten glass within the shell; and finally causing the plunger to descend to unite the electrode -with its attenuated terminal and to weld the glass with the electrode and shell.

4. The method herein described of manufacturing s ark plugs which consists in supporting an embracing the heated shell within a mold; heating an electrode and frictionally supporting it within the lower extremity'of a compressing plunger; depositing a body of molten glass within the shell; and automatically locating the electrode with reference to the shell and welding the glass with the shell and electrode by causing the plunger to descend within the mold and upon the molten glass within the shell.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

JAMES C. ANDERSON.

Witnesses:

D. G. STUART, HENRY C. HAZARD. 

